2. Tags are usually added according to the main idea of the article after writing.

3. Tags can extract key words from articles, which have the meaning of keywords, but the contents do not.

4. Labels reflect your main concerns.

5. Labels give us a link to contact others.

6. The directory can only be a tree structure, that is, the relationship between the parent directory and the sub-directory, and the complicated classification relationship of articles can be realized by using tags.